Method of making reinforced paper bags



Oct. 8, -1-940. e. w. POPPE 2,217,493

I METHOD OF MAKING REINFORCED PAPER BAGS Filed Oct. 11. 1939 2 Sheets-Sheet l INVENTOR GEO/86E 14/ POP/"f ATTORNEY l i 1 I l 1 P J i i 32 .32

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Oct. 8, 1940. w PQPPE 2,217,493

METHOD OF MAKING REINFORCED PAPER BAGS Filed Oct. 11, 1939 2 Sheets-Sheet 2 INVENTOR 7- 650264-- W Pop/ 5 ATTORNEY Patented Oct. 8, 1940 UNITED STATES 2,217,493 METHOD OF MAKHggiElNFOROED PAPER George W. Poppe, Brooklyn, N. 'Y., assignor to I Equitable Paper Bag 60. Inc., Brooklyn, N. Y., a corporation of New York Application October 11, 1939, Serial No. 298,880

I 2 Claims. (Cl. 98-35) The present invention relates to a method of producing a paper bag of the character shown in my copending application Serial No. 298,881, filed October 11, 1939.

An object of the invention is to produce a bag of this character by a method which lends itself to high speed pr duction on an ordinary bag machine. A furt er object is to provide a method of reinforcing a bag of this type whereby the reinforcing means are formed incidentally to the commercial production. of the bag as distinguished from the use of separate reinforcingelements which are attached to the bag after it has been formed. 9 .g

Various features and advantages in the attainment of these objects will appear from the following description and claims when taken in connection with the accompanying drawings, in which:

' Figure 1 is a longitudinal section of a familiar type of bag machine illustrating how the method may be carried out commercially;

Figure 21s a diagrammatic view illustrating the method;

Figure 3 is an enlarged view of a bag section after having been severed from the bag tube and prior tofolding the bottom;

Figure 4 is the reverse of Figure 2 with the closing flap folded over and the locking tongue folded up;

Figure 5 is a section along the line 5-5 of Figure 6; Figure 6 is a view similar to Figure 1 but showing a slightly modified construction and in addition showing the bottom folded over; and

Figure '7 is a view of the upper portion of Figure 6 with the flap folded down and the locking tongues engaging the folded down flap.

Paper bags having locking tongues engaging a folded over flap at the mouth of the bag have been proposed, but .as far as I am aware, such bags are not capable of being produced at a high rate of speed on a bag machine. The method may be stated that paper bags of this character 50 may be produced at a speed varying from 500 to 800 per minute depending somewhat of course upon the length of the bag. Since these bags are designed to be used as so-called "carry bags, they are necessarily furnished by the retail 5o dealer along with the merchandise purchased and-are therefore a part of the general overhead. A consideration of cost is therefore of paramount importance.

Since the method can best be understood by describing the commercial mannerin which it is 5 carried out, reference will be made to a bag machine of well known type.

Referring to Figure 1, the machine includes side frames i; which support numerous shafts by which the paper out of which the bags are to be 10 formed is fed through the machine and suitably acted upon. A web of paper 5 is fed froma roll 6 and is passed over suitable guide rollers I to a hardened steel roller8 at which point its direction of movement is reversed; the web then pass- 16 ing under aformer l0 over which it is folded to form a bag tube. Feed rollers I2 continuously feed the web and tube towards the left in- Figure '1. As the web is fed over the roller 8, it is acted upon by dies l4, Figures 1 and 2, which make slightly oblique cutsin the web, these cuts being indicated at I5, Figure 2, said cuts determining the side edges of the closing flap'in the finished bag. When the web reaches the feed rollers I 2 it is in the form of a tube and is ready to be 25 severed into bag sections from which the completed bag is made by closing the bottom of each section. The severing mechanism includes the serrated edge of the former indicated at it, Figure 1, and a lip knife lame edge'of which is 30 of irregular shape' as shown in Figure 2. The central portion of the lip knife is of trapezoidal form as indicated at 20 (Figure 2), so that when ,the walls of the tube are severed by the joint cooperation of the former edge, the lip knife and 35 the striker bar 22, Figure 1, carried by the sprocket chain 23, a recess indicated at 24, Figure 3, is formed at one end of one bag'wall and a projection is formed at the opposite end of the same wall. The endsof the other wall are alike and 40 are cut straight across.

The edge of the former and the edge of the .lipknife are spaced apart so that the resulting tube section has its respective walls longitudinally offset. Since the bottom of one bag section constitutes the top of the succeeding bag section, it follows that the severed. section shown at x, Figure 2, has the recess 24 at one end and a complemental projection 26 at its other end. Figure 3 is the same as section X but somewhat enlarged. ,After each section has been severed from the main tube, through the action of the severing mechanism in cooperation ,with the so-called pinch bars 21, a section is passed between rollers 28, the upper one of which carries a die 30 which forms a tonguein both bag walls, said tongue being indicated at 32, Figure 2-K and Figure 3. The section then passes to bottoming mechanism indicated generally by the reference character 33, Figure 1. With the exception of the die 30, the machine so far described is substantially the same as that illustrated and described in my Reissue Patent 19,921, April '7, 1936.

By-reason of the diagonal cuts l5 made by the dies H, the upper portion of each bag section has formed thereon a flap 35 which is designed to close the mouth of the bag when folded over to the position shown in Figure 4. The bottom of the bag, however, is provided with a recess which out'the recess 24 is described in my aforesaid reissue patent and by reason of the formation of the gussets 36, a smaller bottom is obtainable.

The present method preserves the smallbot- 'tom feature but by reason of the shape of the lip knife warm the consequent production of the recess 24 and the projection 26, the bag is not only provided with a short bottom, but with a reinforced bottom since the projection 26 is of a width substantially equal to one-third of the width of the bag.

The novel features of this bag are described and claimed in my copending application Serial No. 298,881 filed of even date herewith.

In Figure 3, the seam wall of the bag is designated 2 and the front or face wall shown in Figure 4, as l. It is to be understood that the lower portion of the bag section shown in Figure 3 is 'folded along the .line aa' onto the wall 2 and pasted thereto by a line of paste supplied by a paste bar 38, Figure 1, paste being received from a pastepot 40 as is usual in machines of this type. This paste line is also shown at 4|, Figure 3.

The type of bag shown in Figures 6 and '7 may ing the two pairs of tongues 32 shown in Figures 6, and 7. Thesetongues are so formed that they lock into the recess 24, as shown in Figures 4 and '7.

The web may be overlapped to form a wide seam near the center of the bag which is wideroller 1 underneath the web 5 and in order that it may properly be secured to the main web, said main web-is supplied with two lines of paste by a roller 44, Figure 1, the lines of paste being separated a distance which is slightly less than the width of the reinforcing strip. These paste lines are indicated at 45, Figure 2; The web 5 is also supplied with a line of paste 4'! at its edge in the usual manner, by a paste roller 46, Figures 1 and 2. The reinforcing strip 42, is therefore pasted to the main web as the two are fed along and is inside of the tube when such tube is formed by the folding over of the web as will clearly appear from Figures 1 and 2. When the reinforcing strip is used, the main seam is offset as shown in Figure 3 at '48. Ofcourse, it'is obvious that a center seam may be used, if desired, and may be so used in Figures 6 and 7 constructions, such center seam aiding to reinforce the web of bag material between the openings formed by the tongues 32.

What I claim is:

1. The method of making a paper bag which consists'in making oblique cuts in a web of paper within the margin thereof, folding saidweb to form a bag tube, continuously advancing the weband tube, severing one wall of said tube along a straight line meeting one end of said oblique cuts and the other wall along an irregular line connecting the other ends of the same cuts, said in both bag walls of a size and shape to fit into said recess when said flap is folded over onto the opposite bag wall, and subsequently closing the bottom of the bag by folding along a line including said projections but not including the remainder of the bag wallof which said projection forms a continuation.

2. The method of making a paper bag which consists in folding a web of paper to form a tube,

continuously advancing the web and tube, severing one wall of said tube along a line transverse of the tube and the-other wall along an irregular line to produce a recess at one end of said wall and a complementary projection at the other end of the same wall, said walls being offset longitudinally, the end of one wall provided with a recess constituting a closing flap at the bag mouth, forming tongues in both bag walls of a size and shape to fit into said recess in said closing flap when said flap is folded over onto the opposite bag wall. GEORGE W. POPPE. 

